Date:	Fri, 13 Feb 2015 16:15:01 +0800
From:	addy ke <addy.ke@...k-chips.com>
To:	alim.akhtar@...il.com, a.hajda@...sung.com
CC:	robh+dt@...nel.org, pawel.moll@....com, mark.rutland@....com,
	ijc+devicetree@...lion.org.uk, galak@...eaurora.org,
	rdunlap@...radead.org, tgih.jun@...sung.com,
	jh80.chung@...sung.com, chris@...ntf.net, ulf.hansson@...aro.org,
	dinguyen@...era.com, heiko@...ech.de, olof@...om.net,
	dianders@...omium.org, sonnyrao@...omium.org, amstan@...omium.org,
	djkurtz@...omium.org, huangtao@...k-chips.com,
	devicetree@...r.kernel.org, hl@...k-chips.com,
	linux-doc@...r.kernel.org, yzq@...k-chips.com, zyw@...k-chips.com,
	zhangqing@...k-chips.com, linux-mmc@...r.kernel.org,
	linux-kernel@...r.kernel.org, kever.yang@...k-chips.com
Subject: Re: [PATCH v2 1/2] mmc: dw_mmc: fix bug that cause 'Timeout sending
 command'



On 2015/2/12 21:59, Alim Akhtar wrote:
> On Thu, Feb 12, 2015 at 4:40 PM, Andrzej Hajda <a.hajda@...sung.com> wrote:
>> On 02/12/2015 03:28 AM, addy ke wrote:
>>> Hi Andrzej and Alim
>>>
>>> On 2015/2/12 07:20, Alim Akhtar wrote:
>>>> Hi Andrzej,
>>>>
>>>> On Wed, Feb 11, 2015 at 5:28 PM, Andrzej Hajda <a.hajda@...sung.com> wrote:
>>>>> Hi Alim,
>>>>>
>>>>> On 02/11/2015 03:57 AM, Addy wrote:
>>>>>> On 2015/02/10 23:22, Alim Akhtar wrote:
>>>>>>> Hi Addy,
>>>>>>>
>>>>>>> On Mon, Feb 9, 2015 at 12:55 PM, Addy Ke <addy.ke@...k-chips.com> wrote:
>>>>>>>> Because of some uncertain factors, such as worse card or worse hardware,
>>>>>>>> DAT[3:0](the data lines) may be pulled down by card, and mmc controller
>>>>>>>> will be in busy state. This should not happend when mmc controller
>>>>>>>> send command to update card clocks. If this happends, mci_send_cmd will
>>>>>>>> be failed and we will get 'Timeout sending command', and then system will
>>>>>>>> be blocked. To avoid this, we need reset mmc controller.
>>>>>>>>
>>>>>>>> Signed-off-by: Addy Ke <addy.ke@...k-chips.com>
>>>>>>>> ---
>>>>>>>>   drivers/mmc/host/dw_mmc.c | 28 ++++++++++++++++++++++++++++
>>>>>>>>   1 file changed, 28 insertions(+)
>>>>>>>>
>>>>>>>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>>>>>>>> index 4d2e3c2..b0b57e3 100644
>>>>>>>> --- a/drivers/mmc/host/dw_mmc.c
>>>>>>>> +++ b/drivers/mmc/host/dw_mmc.c
>>>>>>>> @@ -100,6 +100,7 @@ struct idmac_desc {
>>>>>>>>   };
>>>>>>>>   #endif /* CONFIG_MMC_DW_IDMAC */
>>>>>>>>
>>>>>>>> +static int dw_mci_card_busy(struct mmc_host *mmc);
>>>>>>>>   static bool dw_mci_reset(struct dw_mci *host);
>>>>>>>>   static bool dw_mci_ctrl_reset(struct dw_mci *host, u32 reset);
>>>>>>>>
>>>>>>>> @@ -888,6 +889,31 @@ static void mci_send_cmd(struct dw_mci_slot *slot, u32 cmd, u32 arg)
>>>>>>>>                  cmd, arg, cmd_status);
>>>>>>>>   }
>>>>>>>>
>>>>>>>> +static void dw_mci_wait_busy(struct dw_mci_slot *slot)
>>>>>>>> +{
>>>>>>>> +       struct dw_mci *host = slot->host;
>>>>>>>> +       unsigned long timeout = jiffies + msecs_to_jiffies(500);
>>>>>>>> +
>>>>>>> Why 500 msec?
>>>>>> This timeout value is the same as  mci_send_cmd:
>>>>>> static void mci_send_cmd(struct dw_mci_slot *slot, u32 cmd, u32 arg)
>>>>>> {
>>>>>>          struct dw_mci *host = slot->host;
>>>>>>          unsigned long timeout = jiffies + msecs_to_jiffies(500);
>>>>>>          ....
>>>>>> }
>>>>>>
>>>>>> I have not clear that which is suitable.
>>>>>> Do you have any suggestion on it?
>>>>>>>> +       do {
>>>>>>>> +               if (!dw_mci_card_busy(slot->mmc))
>>>>>>>> +                       return;
>>>>>>>> +               cpu_relax();
>>>>>>>> +       } while (time_before(jiffies, timeout));
>>>>>>>> +
>>>>>>>> +       dev_err(host->dev, "Data busy (status %#x)\n",
>>>>>>>> +               mci_readl(slot->host, STATUS));
>>>>>>>> +
>>>>>>>> +       /*
>>>>>>>> +        * Data busy, this should not happend when mmc controller send command
>>>>>>>> +        * to update card clocks in non-volt-switch state. If it happends, we
>>>>>>>> +        * should reset controller to avoid getting "Timeout sending command".
>>>>>>>> +        */
>>>>>>>> +       dw_mci_ctrl_reset(host, SDMMC_CTRL_ALL_RESET_FLAGS);
>>>>>>>> +
>>>>>>> Why you need to reset all blocks? may be CTRL_RESET is good enough here.
>>>>>> I have tested on rk3288, if only reset ctroller, data busy bit will not
>>>>>> be cleaned,and we will still get
>>>>>>
>>>>>> "Timeout sending command".
>>>>>>
>>>>>>>> +       /* Fail to reset controller or still data busy, WARN_ON! */
>>>>>>>> +       WARN_ON(dw_mci_card_busy(slot->mmc));
>>>>>>>> +}
>>>>>>>> +
>>>>>>>>   static void dw_mci_setup_bus(struct dw_mci_slot *slot, bool force_clkinit)
>>>>>>>>   {
>>>>>>>>          struct dw_mci *host = slot->host;
>>>>>>>> @@ -899,6 +925,8 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot, bool force_clkinit)
>>>>>>>>          /* We must continue to set bit 28 in CMD until the change is complete */
>>>>>>>>          if (host->state == STATE_WAITING_CMD11_DONE)
>>>>>>>>                  sdmmc_cmd_bits |= SDMMC_CMD_VOLT_SWITCH;
>>>>>>>> +       else
>>>>>>>> +               dw_mci_wait_busy(slot);
>>>>>>>>
>>>>>>> hmm...I would suggest you to call dw_mci_wait_busy() from inside
>>>>>>> mci_send_cmd(), seems like dw_mmc hangs while sending update clock cmd
>>>>>>> in multiple cases.see [1]
>>>>>>>
>>>>>>> [1]: http://permalink.gmane.org/gmane.linux.kernel.mmc/31140
>>>>>> I think this patch is more reasonable.
>>>>>> So I will resend patches based on this patch.
>>>>>> thank you!
>>>>> I have tested your patches instead [1] above and they do not solve my issue:
>>>>> Board: odroid-xu3/exynos5422/dw_mmc_250a.
>>>>> MMC card: absent, broken-cd quirk
>>>>> SD card: present
>>>>>
>>>> I doubt $SUBJECT patch in current form can resolve you issue. I have
>>>> already given comments on $subject patch.
>>>>
>>>> Can you try out below patch (I have not tested yet) on top of $SUBJECT patch?
>>>>
>>>> =======
>>>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>>>> index b0b57e3..ea87844 100644
>>>> --- a/drivers/mmc/host/dw_mmc.c
>>>> +++ b/drivers/mmc/host/dw_mmc.c
>>>> @@ -101,6 +101,7 @@ struct idmac_desc {
>>>>  #endif /* CONFIG_MMC_DW_IDMAC */
>>>>
>>>>  static int dw_mci_card_busy(struct mmc_host *mmc);
>>>> +static void dw_mci_wait_busy(struct dw_mci_slot *slot);
>>>>  static bool dw_mci_reset(struct dw_mci *host);
>>>>  static bool dw_mci_ctrl_reset(struct dw_mci *host, u32 reset);
>>>>
>>>> @@ -874,16 +875,22 @@ static void mci_send_cmd(struct dw_mci_slot
>>>> *slot, u32 cmd, u32 arg)
>>>>         struct dw_mci *host = slot->host;
>>>>         unsigned long timeout = jiffies + msecs_to_jiffies(500);
>>>>         unsigned int cmd_status = 0;
>>>> +       int re_try = 3; /* just random for now, 1 re-try should be ok */
>>>>
>>>> -       mci_writel(host, CMDARG, arg);
>>>> -       wmb();
>>>> -       mci_writel(host, CMD, SDMMC_CMD_START | cmd);
>>>> +       while(re_try--) {
>>>> +               mci_writel(host, CMDARG, arg);
>>>> +               wmb();
>>>> +               mci_writel(host, CMD, SDMMC_CMD_START | cmd);
>>>>
>>>> -       while (time_before(jiffies, timeout)) {
>>>> -               cmd_status = mci_readl(host, CMD);
>>>> -               if (!(cmd_status & SDMMC_CMD_START))
>>>> -                       return;
>>>> +               while (time_before(jiffies, timeout)) {
>>>> +                       cmd_status = mci_readl(host, CMD);
>>>> +                       if (!(cmd_status & SDMMC_CMD_START))
>>>> +                               return;
>>>> +               }
>>>> +
>>>> +               dw_mci_wait_busy(slot);
>>>>         }
>>>> +
>>>>         dev_err(&slot->mmc->class_dev,
>>>>                 "Timeout sending command (cmd %#x arg %#x status %#x)\n",
>>>>                 cmd, arg, cmd_status);
>>>> @@ -925,8 +932,6 @@ static void dw_mci_setup_bus(struct dw_mci_slot
>>>> *slot, bool force_clkinit)
>>>>         /* We must continue to set bit 28 in CMD until the change is complete */
>>>>         if (host->state == STATE_WAITING_CMD11_DONE)
>>>>                 sdmmc_cmd_bits |= SDMMC_CMD_VOLT_SWITCH;
>>>> -       else
>>>> -               dw_mci_wait_busy(slot);
>>>>
>>>>         if (!clock) {
>>>>                 mci_writel(host, CLKENA, 0);
>>>>
>>>> ===== end ======
>>> The reason why we are fail to send command is that we got data busy in
>>> none-switch-volt state(host->state != STATE_WAITING_CMD11_DONE).
>>> So:
>>> if(host->state != STATE_WAITING_CMD11_DONE), we must wait until data not busy,
>>> And if (host->state == STATE_WAITING_CMD11_DONE) we should not wait.
>>>
>>>>> System hangs during boot after few minutes kernel spits:
>>>>> [  242.188098] INFO: task kworker/u16:1:50 blocked for more than 120
>>>>> seconds.
>>>>> [  242.193524]       Not tainted
>>>>> 3.19.0-next-20150210-00002-gf96831b-dirty #3834
>>>>> [  242.200622] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
>>>>> disables this message.
>>>>> [  242.208422] kworker/u16:1   D c04766ac     0    50      2 0x00000000
>>>>> [  242.214756] Workqueue: kmmcd mmc_rescan
>>>>> [  242.218553] [<c04766ac>] (__schedule) from [<c0476a58>]
>>>>> (schedule+0x34/0x98)
>>>>> [  242.225591] [<c0476a58>] (schedule) from [<c047a4dc>]
>>>>> (schedule_timeout+0x110/0x164)
>>>>> [  242.233302] [<c047a4dc>] (schedule_timeout) from [<c04774f0>]
>>>>> (wait_for_common+0xb8/0x14c)
>>>>> [  242.241539] [<c04774f0>] (wait_for_common) from [<c0362138>]
>>>>> (mmc_wait_for_req+0x68/0x17c)
>>>>> [  242.249861] [<c0362138>] (mmc_wait_for_req) from [<c03622cc>]
>>>>> (mmc_wait_for_cmd+0x80/0xa0)
>>>>> [  242.258002] [<c03622cc>] (mmc_wait_for_cmd) from [<c0367e50>]
>>>>> (mmc_go_idle+0x78/0xf8)
>>>>> [  242.265796] [<c0367e50>] (mmc_go_idle) from [<c0363e2c>]
>>>>> (mmc_rescan+0x280/0x314)
>>>>> [  242.273253] [<c0363e2c>] (mmc_rescan) from [<c0034764>]
>>>>> (process_one_work+0x120/0x324)
>>>>> [  242.281135] [<c0034764>] (process_one_work) from [<c00349cc>]
>>>>> (worker_thread+0x30/0x42c)
>>>>> [  242.289194] [<c00349cc>] (worker_thread) from [<c003926c>]
>>>>> (kthread+0xd8/0xf4)
>>>>> [  242.296389] [<c003926c>] (kthread) from [<c000e7c0>]
>>>>> (ret_from_fork+0x14/0x34)
>>>>>
>>>>> Just for record, Exynos4412/dw_mmc_240a with the same configuration
>>>>> (no MMC card, broken-cd) works OK without patches.
>>> This is because mmc start command,but mmc_request_done() is't called.
>>> I have ever found this issue.
>>> I found that host does't get DTO interrupt when mmc send command to read data.
>>> I have sent a patch for it, see:
>>> https://patchwork.kernel.org/patch/5426531/
>>>
>>> Would you please merge it and test again?
>>
>> I have merged it and added quirk to exynos, but it does not help. There
>> is still timeout:
>>
> I don't think this DTO issue. I think we need a way to reproduce this,
> at least on Exyons5422/5800.
> what type of sd card is being used? Are you trying UHS-I mode by any chance?
> 
Emmc, sd card and sdio, all have this issue on rk3288,
I have NOT found data busy before send command, but still not get DTO interrupt.

And we have ever found little probability of no command done interrupt.

>> [  242.188178] INFO: task kworker/u16:1:50 blocked for more than 120
>> seconds.
>> [  242.193605]       Not tainted
>> 3.19.0-next-20150212-00003-g7850750-dirty #3841
>> [  242.200703] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
>> disables this message.
>> [  242.208592] kworker/u16:1   D c04755f4     0    50      2 0x00000000
>> [  242.214840] Workqueue: kmmcd mmc_rescan
>> [  242.218635] [<c04755f4>] (__schedule) from [<c04759a0>]
>> (schedule+0x34/0x98)
>> [  242.225671] [<c04759a0>] (schedule) from [<c0479424>]
>> (schedule_timeout+0x110/0x164)
>> [  242.233383] [<c0479424>] (schedule_timeout) from [<c0476438>]
>> (wait_for_common+0xb8/0x14c)
>> [  242.241619] [<c0476438>] (wait_for_common) from [<c0361600>]
>> (mmc_wait_for_req+0xb0/0x13c)
>> [  242.249848] [<c0361600>] (mmc_wait_for_req) from [<c036170c>]
>> (mmc_wait_for_cmd+0x80/0xa0)
>> [  242.258086] [<c036170c>] (mmc_wait_for_cmd) from [<c03676e0>]
>> (mmc_go_idle+0x78/0xf8)
>> [  242.265876] [<c03676e0>] (mmc_go_idle) from [<c0363700>]
>> (mmc_rescan+0x25c/0x2e4)
>> [  242.273333] [<c0363700>] (mmc_rescan) from [<c0034764>]
>> (process_one_work+0x120/0x324)
>> [  242.281216] [<c0034764>] (process_one_work) from [<c00349cc>]
>> (worker_thread+0x30/0x42c)
>> [  242.289275] [<c00349cc>] (worker_thread) from [<c003926c>]
>> (kthread+0xd8/0xf4)
>> [  242.296469] [<c003926c>] (kthread) from [<c000e7c0>]
>> (ret_from_fork+0x14/0x34)
>>
>>
>> Regards
>> Andrzej
>>
>>>>>
>>>>> Regards
>>>>> Andrzej
>>>>>
>>>>>>>>          if (!clock) {
>>>>>>>>                  mci_writel(host, CLKENA, 0);
>>>>>>>> --
>>>>>>>> 1.8.3.2
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> _______________________________________________
>>>>>>>> linux-arm-kernel mailing list
>>>>>>>> linux-arm-kernel@...ts.infradead.org
>>>>>>>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>>>>>>>
>>>>>>
>>>>>> --
>>>>>> To unsubscribe from this list: send the line "unsubscribe linux-doc" in
>>>>>> the body of a message to majordomo@...r.kernel.org
>>>>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>>>>>
>>>>
>>>>
>>>
>>
> 
> 
> 
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